Pneumatic tire with sealant

Abstract

The present invention is directed to a pneumatic tire comprising a tread portion having (i) circumferential grooves and (ii) circumferential ribs or rows of tread blocks; an inner surface defining a tire cavity; and a sealant material layer at least partially covering the inner surface radially below the tread portion within the tire cavity. The sealant material layer comprises elevations of sealant material, wherein an elevation of sealant material is provided radially below each of at least two of the circumferential grooves, and wherein the sealant material layer has a larger radial thickness in said elevations than in areas radially below the circumferential ribs or rows of tread blocks.

What is claimed is: 
     
         1 . A pneumatic tire comprising a tread portion having (i) circumferential grooves and (ii) circumferential ribs or rows of tread blocks; an inner surface defining a tire cavity; and a sealant material layer at least partially covering the inner surface radially below the tread portion within the tire cavity, the sealant material layer comprising elevations of sealant material, wherein an elevation of sealant material is provided radially below each of at least two of the circumferential grooves, and wherein the sealant material layer has a larger radial thickness in said elevations than in areas radially below the circumferential ribs or rows of tread blocks. 
     
     
         2 . The pneumatic tire according to  claim 1 , wherein each elevation has an axial width within a range of 70% to 130% of an axial width of a bottom of a circumferential groove radially above the respective elevation. 
     
     
         3 . The pneumatic tire according to  claim 1 , wherein a radial thickness of an elevation of two neighboring elevations, measured from the inner surface of the tire to the radially innermost surface of the respective elevation, is one or more of:
 at least 15% larger than a radial thickness of the sealant material layer in the middle between the two neighboring elevations; and   at most 100% larger than a radial thickness of the sealant material layer in the middle between the two neighboring elevations.   
     
     
         4 . The pneumatic tire according to  claim 1 , the tire comprising at least three circumferential grooves and at least four circumferential ribs or rows of tread blocks. 
     
     
         5 . The pneumatic tire according to  claim 1 , wherein an elevation of the sealant material is provided radially below each of said circumferential grooves. 
     
     
         6 . The pneumatic tire according to  claim 1 , wherein the largest radial thickness of the elevations is within a range of 3 mm to 9 mm, measured from the inner surface of the tire to the radially innermost surface of the respective elevation. 
     
     
         7 . The pneumatic tire according to  claim 1 , wherein a radial thickness of the sealant material layer in the middle between two neighboring elevations is within a range of 2 mm to 6 mm. 
     
     
         8 . The pneumatic tire according to  claim 1 , wherein a difference between i) a radial thickness of the sealant layer in the middle between two neighboring elevations and ii) a largest radial thickness of one of the neighboring elevations, is at least 0.5 mm. 
     
     
         9 . The pneumatic tire according to  claim 1 , wherein the sealant material layer extends in an axial direction over at least 90% of the width of said tread portion. 
     
     
         10 . The pneumatic tire according to  claim 1 , wherein the sealant material comprises one or more of: a butyl rubber-based composition, a polyisoprene-based composition, a natural rubber-based composition, a polyurethane-based composition, a polybutene-based composition, an emulsion styrene-butadiene rubber-based composition, an EPDM-based composition, and a silicone-based composition. 
     
     
         11 . The pneumatic tire according to  claim 1 ,
 wherein the sealant material layer comprises one of:   (i) axially adjacent sealant material strips extending circumferentially about an axis of the tire and along the inner surface of the tire, and   (ii) one or more sealant material strips spirally wound about an axis of the tire and along the inner surface of the tire.   
     
     
         12 . The pneumatic tire according to  claim 11 , wherein the sealant material strips form the elevations and the areas of the sealant material layer radially below the circumferential ribs or rows of tread blocks, and wherein at least multiple sealant material strips are one or more of:
 radially thicker in areas radially below the circumferential grooves than in the areas radially below the circumferential ribs or rows of tread blocks so as to form the elevations in the sealant material layer;   arranged on top of one another so as to form the elevations in the sealant material layer.   
     
     
         13 . The pneumatic tire according to  claim 1 , wherein the tread portion has two shoulder portions and a center portion axially between the two shoulder portions, and wherein each shoulder portion comprises a circumferential shoulder rib or row of shoulder tread blocks, and the center portion comprises at least three circumferential ribs and at least four circumferential grooves, and wherein each shoulder rib is delimited by one of the at least four circumferential grooves. 
     
     
         14 . The pneumatic tire according to  claim 1 , wherein the elevations in the sealant material layer and areas of the sealant material layer having a radial thickness smaller than the radial thickness of said elevations alternate along an axial direction of the tire. 
     
     
         15 . The pneumatic tire according to  claim 1 , wherein said areas of the sealant material layer having a radial thickness smaller than the radial thickness of said elevations have an axial width within a range of 60% to 120% of the radially outermost surface of the respective rib or respective row of tread blocks radially above. 
     
     
         16 . The pneumatic tire according to  claim 1 , wherein at least one foam element is attached to a radially inner surface of at least two axially neighboring elevations such that at least one air cavity is formed between said axially neighboring elevations, a radially outer surface of the foam element and a radially inner surface of the sealant material layer between said axially neighboring elevations. 
     
     
         17 . The pneumatic tire according to  claim 16 , wherein the foam element is a foam strip extending in a circumferential direction along a circumferential length corresponding to at least 50%, preferably at least 80%, of an inner circumference of the tire, measured along the inner surface at an axial center of the tire. 
     
     
         18 . The pneumatic tire according to  claim 16 , wherein the axial width of the foam element is within a range of 20% to 50% of a maximum axial width of the sealant material layer. 
     
     
         19 . The pneumatic tire according to  claim 16 , wherein the foam element is free of a coating or foil facing the sealant material layer. 
     
     
         20 . The pneumatic tire according to  claim 16 , wherein the foam element comprises one or more of:
 a noise dampening material;   a polymeric foam material;   a polyurethane foam material;   a strip shape; and   a material having a density within a range of 0.01 g/cm 3  to 1 g/cm 3 .